Coupling agents for mineral-filled elastomer compositions

ABSTRACT

A composition of matter is disclosed that comprises at least one silane coupling agent for coupling an elastomer and a filler wherein said silane comprises at least one hydrolysable group that, upon compounding said silane with said elastomer and filler, is released to yield a compound that improves downstream processability of the compounded composition or the properties of the final rubber product or both.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to silane coupling agents, methodsfor their preparation, and their use in rubber applications. Moreparticularly, these silanes embody a new concept whose focus is totransform the hydrolysable group, once released from the silane, from awaste product to one that contributes to improvements in theprocessability and properties of the final product.

[0003] 2. Description of Related Art

[0004] A large body of art exists relating to the composition,preparation, and uses of polysulfide silanes and mercaptosilanes inrubber and other applications. There is sufficient interest in thisfield that many of the original patents have begun to expire as newpatents continue to appear. Most of the interest has centered around thesulfur functionality of these molecules. For example, there is a greatnumber of patents dealing with mixtures of polysulfide silanescontaining subtle variations in the sulfur rank distributions (i.e.,variations in the value of x and in the distributions of thecorresponding molecular species, in Formulae 1 and 2, below). Fewer, butnevertheless a sizeable number, of the citations also focus onvariations in the linking group between sulfur and silicon.

[0005] On the other hand, very little attention has been focused on thehydrolysable portion of the molecule beyond attempts at broad coverageof alkoxy groups and in some cases other hydrolysable functionality,usually containing a single, but broadly defined, hydrocarbon groupwhen, in fact, all that was of real interest has been ethoxy and, insome more recent cases, siloxy. Moreover, the hydrolysable group hasbeen implicitly treated as an expendable portion and tolerated as anultimate waste product of the molecule because it is lost during theprocess of using these silanes in their intended application.

[0006] U.S. Pat. No. 5,116,886 discloses a two-stage method for thesuface modification of natural or synthetic, oxide or silicate fillersusing certain organosilicon compounds of a given formula, wherein thefiller and compound are intensively mixed without the addition offurther solvents and homogenized mixture is subjected in a a preheatedmixer to the hydrophobing reaction.

[0007] EP 0 631 982 A2 discloses aggregates comprised of particles thatcontain silicon dioxide, elastomers reinforced therewith, and tireshaving treads composed of such reinforced elastomers.

SUMMARY OF THE INVENTION

[0008] The present invention relates to using hydrolysable groups withan ancilliary use, so that when such groups are released during rubbercompounding, they are neither lost, nor do they end up as waste, but,instead, go on to improve another aspect of the rubber compoundingprocess and/or the properties of the final product.

[0009] More particularly, the present invention is directed to acomposition of matter comprising at least one silane coupling agent forcoupling an elastomer and a filler wherein said silane comprises atleast one hydrolysable group that, upon compounding said silane withsaid elastomer and filler, is released to yield a compound that improvesdownstream processability of the compounded composition or theproperties of the final rubber product or both.

[0010] In a preferred embodiment, The silane is selected from the groupconsisting of silanes whose individual structures are represented by atleast one of the following general formulae:

[J-S-G¹-(SiX²X³)][—Y²—(X²Si-G¹-S-J)]_(m)-X^(1.);  Formula 1:

[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²Si)-G²S_(x)-G³-(SiX¹X²X³)]_(m)—X^(1.);  Formula2:

[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²X³Si)-G²-S_(x)-G³-(SiX²X³)]_(n)—X^(1.);and  Formula 3:

[(—Y²—)_(y/2)(X² _(3-h)Si)-G¹-S-J]_(m)[(—Y²—)_(j/2)(X²_(3-j)Si)-G²-S_(x)-G³-(SiX² _(3-k))(—Y²—)_(k/2)]_(n)  Formula 4:

[0011] wherein, in formulae 1 through 4:

[0012] each occurrence of the subscript, h, is independently an integerfrom 1 to 3;

[0013] each separate occurrence of the subscripts, j and k, isindependently an integer from 0 to 3, with the proviso that j+k>0;

[0014] each occurrence of the subscript, m, is independently an integerfrom 1 to 1000;

[0015] each occurrence of the subscript, n, is independently an integerfrom 1 to 1000;

[0016] each occurrence of the subscript, x, is independently an integerfrom 2 to 20;

[0017] each occurrence of X¹ is independently selected from the group ofhydrolysable moieties consisting of —Y¹, —OH, —OR¹, and R¹C(═O)O—,wherein each occurrence of R¹ is independently any hydrocarbon fragmentobtained by removal of one hydrogen atom from a hydrocarbon having from1 to 20 carbon atoms, and R¹ includes aryl groups and any branched orstraight chain alkyl, alkenyl, arenyl, or aralkyl groups;

[0018] each occurrence of X² and X³ is independently selected from thegroup consisting of hydrogen, R¹, and X^(1.);

[0019] each occurrence of G¹, G², and G³ is independently selected fromthe group consisting of hydrocarbon fragments obtained by removal of onehydrogen atom of any of the groups listed above for R^(1.);

[0020] each occurrence of J is independently selected from the groupconsisting of R¹C(═O)—, R¹C(═S)—, R¹ ₂P(═O)—, R¹ ₂P(═S)—, R¹S(═O)—, andR¹S(═O)₂—, wherein each separate occurrence of R¹ is as defined above;

[0021] each occurrence of Y¹ is independently —O-G-(O-G-)_(p)OR or—O-G-(O-G-)_(p)OH and each occurrence of Y² is independently—O-G-(O-G-)_(q)O—,

[0022] each occurrence of the subscript, p, is independently an integerfrom 1 to 100;

[0023] each occurrence of the subscript, q, is independently an integerfrom 1 to 100;

[0024] each occurrence of G is independently selected from the groupconsisting of hydrocarbon fragments obtained by removal of one hydrogenatom of any of the groups listed above for R^(1.); and

[0025] each occurrence of R is independently selected from the groupconsisting of the members listed above for R¹.

[0026] In another embodiment, the present invention is directed to acomposition comprising:

[0027] A) at least one elastomer;

[0028] B) at least one filler; and

[0029] C) at least one silane coupling agent for coupling the elastomerand the filler wherein the silane comprises at least one hydrolysablegroup that, upon compounding said silane with said elastomer and filler,is released to yield a compound that improves downstream processabilityof the compounded composition or the properties of the final rubberproduct or both.

[0030] In still another embodiment, the present invention is directed toa method for coupling an elastomer and a filler, wherein the methodcomprises employing at least one silane coupling agent wherein saidsilane comprises at least one hydrolysable group that, upon compoundingsaid silane with said elastomer and filler, is released to yield acompound that improves downstream processability of the compoundedcomposition or the properties of the final rubber product or both.

[0031] In still another embodiment, the present invention is directed toa method for preparing a silane coupling agent for coupling an elastomerand a filler wherein said silane comprises at least one hydrolysablegroup that, upon compounding said silane with said elastomer and filler,is released to yield a compound that improves downstream processabilityof the compounded composition or the properties of the final rubberproduct or both, wherein said method comprises transesterifying TESPTwith a polyalkylene glycol.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The coupling agents useful herein comprise any individualcomponent or mixture of components whose individual structures can berepresented by one or more of the following general formulae:

[J-S-G¹-(SiX²X³)][—Y²—(X²Si-G¹-S-J)]_(m)-X^(1.);  Formula 1:

[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²Si)-G²S_(x)-G³-(SiX¹X²X³)]_(m)—X^(1.);  Formula2:

[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²X³Si)-G²-S_(x)-G³-(SiX²X³)]_(n)—X^(1.);and  Formula 3:

[(—Y²—)_(y/2)(X² _(3-h)Si)-G¹-S-J]_(m)[(—Y²—)_(j/2)(X²_(3-j)Si)-G²-S_(x)-G³-(SiX² _(3-k))(—Y²—)_(k/2)]_(n)  Formula 4:

[0033] wherein, in formulae 1 through 4:

[0034] each occurrence of the subscript, h, is independently an integerfrom 1 to 3;

[0035] each separate occurrence of the subscripts, j and k, isindependently an integer from 0 to 3, with the proviso that j+k>0;

[0036] each occurrence of the subscript, m, is independently an integerfrom 1 to 1000;

[0037] each occurrence of the subscript, n, is independently an integerfrom 1 to 1000;

[0038] each occurrence of the subscript, x, is independently an integerfrom 2 to 20;

[0039] each occurrence of X¹ is independently selected from the group ofhydrolysable moieties consisting of —Y¹, —OH, —OR¹, and R¹C(═O)O—,wherein each occurrence of R¹ is independently any hydrocarbon fragmentobtained by removal of one hydrogen atom from a hydrocarbon having from1 to 20 carbon atoms, and R¹ includes aryl groups and any branched orstraight chain alkyl, alkenyl, arenyl, or aralkyl groups;

[0040] each occurrence of X² and X³ is independently selected from thegroup consisting of hydrogen, R¹, and X^(1.);

[0041] each occurrence of G¹, G², and G³ is independently selected fromthe group consisting of hydrocarbon fragments obtained by removal of onehydrogen atom of any of the groups listed above for R^(1.);

[0042] each occurrence of J is independently selected from the groupconsisting of R¹C(═O)—, R¹C(═S)—, R¹ ₂P(═O)—, R¹ ₂P(═S)—, R¹S(═O)—, andR¹S(═O)₂—, wherein each separate occurrence of R¹ is as defined above;

[0043] each occurrence of Y¹ is independently —O-G-(O-G-)_(p)OR or—O-G-(O-G-)_(p)OH and each occurrence of Y² is independently—O-G-(O-G-)_(q)O—,

[0044] each occurrence of the subscript, p, is independently an integerfrom 1 to 100;

[0045] each occurrence of the subscript, q, is independently an integerfrom 1 to 100;

[0046] each occurrence of G is independently selected from the groupconsisting of hydrocarbon fragments obtained by removal of one hydrogenatom of any of the groups listed above for R^(1.); and

[0047] each occurrence of R is independently selected from the groupconsisting of the members listed above for R¹.

[0048] As used herein, the notation, (—Y²—)_(0.5), refers to one half ofthe Y² moiety. This notation is used in conjunction with a silicon atomand is taken to mean one-half of a bis-functional alkoxide, namely, thehalf bound to the particular silicon atom. It is understood that theother half of the bis-functional alkoxide moiety and its bond to siliconoccurs somewhere else in the overall structure of the molecule.

[0049] Representative examples of X¹ include methoxy, ethoxy, propoxy,isopropoxy, butoxy, phenoxy, benzyloxy, hydroxy, chloro, and acetoxy.Methoxy, ethoxy, and isopropoxy are preferred. Ethoxy is more preferred.

[0050] Representative examples of X² and X³ include the representativeexamples listed above for X¹ as well as hydrogen, methyl, ethyl, propyl,isopropyl, sec-butyl, phenyl, vinyl, cyclohexyl, and higherstraight-chain alkyl, such as butyl, hexyl, octyl, lauryl, andoctadecyl. Methoxy, ethoxy, isopropoxy, methyl, ethyl, phenyl, and thehigher straight-chain alkyls are preferred for X² and X³. Ethoxy,methyl, and phenyl are more preferred. The preferred embodiments alsoinclude those in which X¹, X², and X³ are the same alkoxy group,preferably methoxy, ethoxy, or isopropoxy. Ethoxy is most preferred.

[0051] Representative examples of G¹, G², and G³ include the terminalstraight-chain alkyls further substituted terminally at the oppositeend, such as —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, and—CH₂CH₂CH₂CH₂CH₂CH₂CH₂CH₂—, and their beta-substituted analogs, such as—CH₂(CH₂)_(m)CH(CH₃)—, where m is zero to 17; —CH₂CH₂C(CH₃)₂CH₂—; thestructure derivable from methallyl chloride, —CH₂CH(CH₃)CH₂—; any of thestructures derivable from divinylbenzene, such as —CH₂CH₂(C₆H₄)CH₂CH₂—and —CH₂CH₂(C₆H₄)CH(CH₃)—, where the notation C₆H₄ denotes adisubstituted benzene ring; any of the structures derivable fromdipropenylbenzene, such as —CH₂CH(CH₃)(C₆H₄)CH(CH₃)CH₂—, where thenotation C₆H₄ denotes a disubstituted benzene ring; any of thestructures derivable from butadiene, such as —CH₂CH₂CH₂CH₂—,—CH₂CH₂CH(CH₃)—, and —CH₂CH(CH₂CH₃)—; any of the structures derivablefrom piperylene, such as —CH₂CH₂CH₂CH(CH₃)—, —CH₂CH₂CH(CH₂CH₃)—, and—CH₂CH(CH₂CH₂CH₃)—; any of the structures derivable from isoprene, suchas —CH₂CH(CH₃)CH₂CH₂—, —CH₂CH(CH₃)CH(CH₃)—, —CH₂C(CH₃)(CH₂CH₃)—,—CH₂CH₂CH(CH₃)CH₂—, —CH₂CH₂C(CH₃)₂—, and —CH₂CH[CH(CH₃)₂]—; any of theisomers of —CH₂CH₂-norbornyl-, —CH₂CH₂-cyclohexyl-; any of thediradicals obtainable from norbornane, cyclohexane, cyclopentane,tetrahydrodicyclopentadiene, or cyclododecene by loss of two hydrogenatoms; any of the structures derivable from limonene,—CH₂CH(4-methyl-1-C₆H₉—)CH₃, where the notation C₆H₉ denotes isomers ofthe trisubstituted cyclohexane ring lacking substitution in the 2position; any of the monovinyl-containing structures derivable fromtrivinylcyclohexane, such as —CH₂CH₂(vinylC₆H₉)CH₂CH₂— and—CH₂CH₂(vinylC₆H₉)CH(CH₃)—, where the notation C₆H₉ denotes any isomerof the trisubstituted cyclohexane ring; any of the monounsaturatedstructures derivable from myrcene containing a trisubstituted C═C, suchas —CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH₂CH₂—, —CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH(CH₃)—,—CH₂C[CH₂CH₂CH═C(CH₃)₂](CH₂CH₃)—, —CH₂CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH₂—,—CH₂CH₂(C—)(CH₃)[CH₂CH₂CH═C(CH₃)2], and—CH₂CH{CH(CH₃)[CH₂CH₂CH═C(CH₃)₂]}—; and any of the monounsaturatedstructures derivable from myrcene lacking a trisubstituted C═C, such as—CH₂CH(CH═CH₂)CH₂CH₂CH₂C(CH₃)₂—, —CH₂CH(CH═CH₂)CH₂CH₂CH[CH(CH₃)₂]—,—CH₂C(═CH—CH₃)CH₂CH₂CH₂C(CH₃)₂—, —CH₂C(═CH—CH₃)CH₂CH₂CH[CH(CH₃)₂]—,CH₂CH₂C(═CH₂)CH₂CH₂CH₂C(CH₃)₂—, —CH₂CH₂C(═CH₂)CH₂CH₂CH[CH(CH₃)₂]—,—CH₂CH═C(CH₃)₂CH₂CH₂CH₂C(CH₃)₂—, and —CH₂CH═C(CH₃)₂CH₂CH₂CH[CH(CH₃)₂].The preferred structures for G¹, G², and G³ are —CH₂—, —CH₂CH₂—,—CH₂CH₂CH₂—, —CH₂CH(CH₃)CH₂—, and any of the diradicals obtained by 2,4or 2,5 disubstitution of the norbornane-derived structures listed above.—CH₂CH₂CH₂— is most preferred.

[0052] Representative examples of J include carboxyl, such as acetyl,propionyl, butanoyl (butyryl), hexanoyl (caproyl), octanoyl (capryloyl),decanoyl, dodecanoyl (lauroyl), tetradecanoyl (myristoyl), hexadecanoyl(palmitoyl), octadecanoyl (stearoyl), and benzoyl; thionocarboxyl, suchas thionoacetyl, thionoloctanoyl, and thionobenzoyl; phosphinic, such asdimethyl phosphinic and diethyl phosphinic; and sulfonyl, such asmethanesulfonyl, benzenesulfonyl, and toluenesulfonyl.

[0053] Representative examples of G include terminal straight-chainalkyls further substituted terminally at the opposite end, such as—CH₂CH₂—, —CH₂CH₂CH₂—, and —CH₂CH₂CH₂CH₂CH₂CH₂—, their beta-substitutedanalogs, such as —CH₂CH(CH₃)—, and analogs with more than one methylsubstitution, such as —CH₂C(CH₃)₂CH₂— and —C(CH₃)₂C(CH₃)₂—;—CH₂CH₂C(CH₃)₂CH₂—; any of the structures derivable from divinylbenzene,such as —CH₂CH₂(C₆H₄)CH₂CH₂— and —CH₂CH₂(C₆H₄)CH(CH₃)—, where thenotation C₆H₄ denotes a disubstituted benzene ring; any of thestructures derivable from dipropenylbenzene, such as—CH₂CH(CH₃)(C₆H₄)CH(CH₃)CH₂—, where the notation C₆H₄ denotes adisubstituted benzene ring; any of the structures derivable frombutadiene, such as —CH₂CH₂CH₂CH₂—, —CH₂CH₂CH(CH₃)—, and —CH₂CH(CH₂CH₃)—;any of the structures derivable from piperylene, such as—CH₂CH₂CH₂CH(CH₃)—, —CH₂CH₂CH(CH₂CH₃)—, and —CH₂CH(CH₂CH₂CH₃)—; any ofthe structures derivable from isoprene, such as —CH₂CH(CH₃)CH₂CH₂—,—CH₂CH(CH₃)CH(CH₃)—, —CH₂C(CH₃)(CH₂CH₃)—, —CH₂CH₂CH(CH₃)CH₂—,—CH₂CH₂C(CH₃)₂—, and —CH₂CH[CH(CH₃)₂]—; any of the monovinyl-containingstructures derivable from trivinylcyclohexane, such as—CH₂CH₂(vinylC₆H₉)CH₂CH₂— and —CH₂CH₂(vinylC₆H₉)CH(CH₃)—, where thenotation C₆H₉ denotes any isomer of the trisubstituted cyclohexane ring;any of the monounsaturated structures derivable from myrcene containinga trisubstituted C═C, such as —CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH₂CH₂—,—CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH(CH₃)—, —CH₂C[CH₂CH₂CH═C(CH₃)₂](CH₂CH₃)—,—CH₂CH₂CH[CH₂CH₂CH═C(CH₃)₂]CH₂—, —CH₂CH₂(C—)(CH₃)[CH₂CH₂CH═C(CH₃)2], and—CH₂CH {CH(CH₃)[CH₂CH₂CH═C(CH₃)₂]}—; and any of the monounsaturatedstructures derivable from myrcene lacking a trisubstituted C═C, such as—CH₂CH(CH═CH₂)CH₂CH₂CH₂C(CH₃)₂—, —CH₂CH(CH═CH₂)CH₂CH₂CH[CH(CH₃)₂]—,—CH₂C(═CH—CH₃)CH₂CH₂CH₂C(CH₃)₂—, —CH₂C(═CH—CH₃)CH₂CH₂CH[CH(CH₃)₂]—,—CH₂CH₂C(═CH₂)CH₂CH₂CH₂C(CH₃)₂—, —CH₂CH₂C(═CH₂)CH₂CH₂CH[CH(CH₃)₂]—,—CH₂CH═C(CH₃)₂CH₂CH₂CH₂C(CH₃)₂—, and —CH₂CH═C(CH₃)₂CH₂CH₂CH[CH(CH₃)₂].The preferred structures for G are —CH₂CH₂— and —CH₂CH(CH₃)—. Mostpreferred is —CH₂CH₂—.

[0054] Representative examples of Y¹ include products derivable bymethanol or ethanol addition to ethylene oxide, such as CH₃OCH₂CH₂O—(methoxyethoxy), which is the alkoxy group derivable frommethoxyethanol; CH₃CH₂OCH₂CH₂O— (ethoxyethoxy), which is the alkoxygroup derivable from ethoxyethanol; CH₃OCH₂CH₂OCH₂CH₂O—(methoxyethoxyethoxy), which is the alkoxy group derivable frommethoxyethoxyethanol; CH₃CH₂OCH₂CH₂OCH₂CH₂O— (ethoxyethoxyethoxy), whichis the alkoxy group derivable from ethoxyethoxyethanol; and oligomericanalogs of these structures containing longer —CH₂CH₂O— repeat units.Additional representative examples of Y¹ include products derivable bymethanol or ethanol addition to propylene oxide, such asCH₃OCH₂CH(CH₃)O— and CH₃OCH(CH₃)CH₂O— (the two isomers ofmethoxyisopropoxy), which are the alkoxy groups derivable from therespective two isomers of methoxyisopropanol; CH₃CH₂OCH₂CH(CH₃)O— andCH₃CH₂OCH(CH₃)CH₂O— (the two isomers of ethoxyisopropoxy, which are thealkoxy groups derivable from the respective two isomers ofethoxyisopropanol; and oligomeric analogs of these structures containinglonger —CH₂CH(CH₃)O— and —CH(CH₃)CH₂O— repeat units in varied sequences.

[0055] As used herein, “alkyl” includes straight, branched, and cyclicalkyl groups; “alkenyl” includes any straight, branched, or cyclicalkenyl group containing one or more carbon-carbon double bonds, wherethe point of substitution can be either at a carbon-carbon double bondor elsewhere in the group; and “alkynyl” includes any straight,branched, or cyclic alkynyl group containing one or more carbon-carbontriple bonds and, optionally, one or more carbon-carbon double bonds aswell, where the point of substitution can be either at a carbon-carbontriple bond, a carbon-carbon double bond, or elsewhere in the group.Specific examples of alkyls include methyl, ethyl, propyl, and isobutyl.Specific examples of alkenyls include vinyl, propenyl, allyl, methallyl,ethylidenyl norbornane, ethylidene norbornyl, ethylidenyl norbornene,and ethylidene norbornenyl. Specific examples of alkynyls includeacetylenyl, propargyl, and methylacetylenyl.

[0056] As used herein, “aryl” includes any aromatic hydrocarbon fromwhich one hydrogen atom has been removed; “aralkyl” includes any of theaforementioned alkyl groups in which one or more hydrogen atoms havebeen substituted by the same number of like and/or different aryl (asdefined herein) substituents; and “arenyl” includes any of theaforementioned aryl groups in which one or more hydrogen atoms have beensubstituted by the same number of like and/or different alkyl (asdefined herein) substituents. Specific examples of aryls include phenyland naphthalenyl. Specific examples of aralkyls include benzyl andphenethyl. Specific examples of arenyls include tolyl and xylyl.

[0057] As used herein, “cyclic alkyl”, “cyclic alkenyl”, and “cyclicalkynyl” also include bicyclic, tricyclic, and higher cyclic structures,as well as the aforementioned cyclic structures further substituted withalkyl, alkenyl, and/or alkynyl groups. Representative examples includenorbornyl, norbornenyl, ethylnorbornyl, ethylnorbornenyl,ethylcyclohexyl, ethylcyclohexenyl, cyclohexylcyclohexyl, andcyclododecatrienyl.

[0058] The etheralkoxy sulfur silanes described herein can be preparedby transesterification of any single-component or combination ofpolysulfide-functional, mercapto-functional, or blockedmercapto-functional silane(s) containing alkoxy, acyloxy, etheralkoxy,and/or hydroxy functionality, with the appropriate starting etheralcoholin the presence of a suitable catalyst, optionally in the presence of asuitable solvent and/or cosolvent. The term “transesterification”, asused herein to describe the preparation of the etheralkoxy sulfursilanes, refers to the replacement of alkoxy, etheralkoxy, and/oracyloxy groups on silicon by an etheralkoxy group, which is accomplishedby reacting an etheralcohol with one or more than one suitable startingsilane(s), to release an alcohol, carboxylic acid, and/or etheralcohol,with the formation of the desired etheralkoxy sulfur silane Suitablestarting silanes are given by Formulae 5 and 6 below, in which J, X¹,X², X³, G¹, G², G³, and the subscript, x, are as described above forFormulae 1, 2, 3, and 4.

J-S-G¹-SiX¹X²X³  Formula 5:

X¹X²X³Si-G²-S_(x)-G³-SiX¹X²X³  Formula 6:

[0059] Appropriate starting etheralcohols are given by Formulae 7 and 8below, in which R, G, and the subscripts, p and q, are as describedabove for Formulae 1, 2, 3, and 4.

RO-G-(O-G-)_(p)OH  Formula 7:

HO-G-(O-G-)_(q)OH  Formula 8:

[0060] Suitable catalysts for the transesterification described hereininclude acids, bases, and metal or organometal cations. Examples ofsuitable acids include sulfonic acids, such as para-toluenesulfonic acid(PTSA), methanesulfonic acid, benzenesulfonic acid; mineral acids, suchas sulfuric acid, HCl, HBr, and phosphoric acid; carboxylic acids, suchas formic acid, acetic acid, and octanoic acid; and Lewis acids, such asaluminum chloride and boron halides. HCl, benzenesulfonic acid andp-toluenesulfonic acid are preferred. Benzenesulfonic acid andp-toluenesulfonic acid are most preferred. Examples of suitable basesinclude alkali metal hydroxides, alkali metal alkoxides, amines, andammonia. Alkali metal alkoxides and ammonia are preferred. Ammonia andNaOR, where R is the same as the R in the starting silane used, are mostpreferred.

[0061] Suitable solvents include, but are not limited to, alcohols,ethers, hydrocarbons, halocarbons, ketones, aromatics, heteroaromatics,formamides, and sulfoxides. Alcohols are preferred. Alcohols, ROH, inwhich R is the same as the R in the starting silane used, are mostpreferred.

[0062] The elastomers useful with the etheralkoxy sulfur silanescoupling agents described herein include sulfur vulcanizable rubbersincluding conjugated diene homopolymers and copolymers, and copolymersof at least one conjugated diene and aromatic vinyl compound. Suitableorganic polymers for preparation of rubber compositions are well knownin the art and are described in various textbooks including TheVanderbilt Rubber Handbook, Ohm, R. F., R.T. Vanderbilt Company, Inc.,1990 and in the Manual for the Rubber Industry, Kemperman, T and Koch,S. Jr., Bayer AG, LeverKusen, 1993.

[0063] The rubber composition preferably comprises at least onediene-based elastomer, or rubber. Suitable conjugated dienes areisoprene and 1,3-butadiene and suitable vinyl aromatic compounds arestyrene and alpha methyl styrene. Polybutadiene can be characterized asexisting primarily (typically about 90% by weight) in thecis-1,4-butadiene form.

[0064] One example of a suitable polymer for use herein issolution-prepared styrene-butadiene rubber (SSBR). This solutionprepared SBR typically has a bound styrene content in a range of 5 to50, preferably 9 to 36, percent. Other useful polymers includestyrene-butadiene rubber (SBR), natural rubber (NR), ethylene-propylenecopolymers and terpolymers (EP, EPDM), acrylonitrile-butadiene rubber(NBR), polybutadiene (BR), and the like. The rubber composition iscomprised of at least one diene-based elastomer, or rubber. Suitableconjugated dienes are isoprene and 1,3-butadiene and suitable vinylaromatic compounds are styrene and alpha methyl styrene. Polybutadienemay be characterized as existing primarily, typically about 90% byweight, in the cis-1,4-butadiene form.

[0065] Thus, the rubber is a sulfur curable rubber. Such diene basedelastomer, or rubber, may be selected, for example, from at least one ofcis-1,4-polyisoprene rubber (natural and/or synthetic, preferablynatural), and preferably natural rubber), emulsion polymerizationprepared styrene/butadiene copolymer rubber, organic solutionpolymerization prepared styrene/butadiene rubber, 3,4-polyisoprenerubber, isoprene/butadiene rubber, styrene/isoprene/butadiene terpolymerrubber, cis-1,4-polybutadiene, medium vinyl polybutadiene rubber (35-50percent vinyl), high vinyl polybutadiene rubber (50-75 percent vinyl),styrene/isoprene copolymers, emulsion polymerization preparedstyrene/butadiene/acrylonitrile terpolymer rubber andbutadiene/acrylonitrile copolymer rubber.

[0066] For some applications, an emulsion polymerization derivedstyrene/butadiene (E-SBR) having a relatively conventional styrenecontent of about 20 to 28 percent bound styrene, or an E-SBR having amedium to relatively high bound styrene content of about 30 to 45percent may be used.

[0067] Emulsion polymerization prepared styrene/butadiene/acrylonitrileterpolymer rubbers containing 2 to 40 weight percent bound acrylonitrilein the terpolymer are also contemplated as diene based rubbers for usein this invention.

[0068] A particulate filler may also be added to the crosslinkableelastomer compositions of the present invention including siliceousfillers, carbon black, and the like. The filler materials useful hereininclude, but are not limited to, metal oxides such as silica (pyrogenicand precipitated), titanium dioxide, aluminosilicate and alumina, claysand talc, carbon black, and the like.

[0069] Particulate, precipitated silica is also sometimes used for suchpurpose, particularly when the silica is used in conjunction with asilane. In some cases, a combination of silica and carbon black isutilized for reinforcing fillers for various rubber products, includingtreads for tires. Alumina can be used either alone or in combinationwith silica. The term, alumina, can be described herein as aluminumoxide, or Al₂O₃. The fillers may be hydrated or in anhydrous form. Useof alumina in rubber compositions can be shown, for example, in U.S.Pat. No. 5,116,886 and EP 631 982.

[0070] The etheralkoxy sulfur silanes release etheralcohols uponreacting with and coupling to the mineral fillers. The releasedetheralcohols provide advantages to the properties of the rubberobtained, as is shown in the examples. Additional etheralcohols may beused to maximize these advantages. The etheralkoxy sulfur silane(s) maybe premixed and/or pre-reacted with one or more etheralcohols in asingle step or more than one step prior to the addition to the rubbermix. Alternatively, the etheralkoxy sulfur silane(s), whether used aloneor premixed and/or prereacted with additional etheralcohol, may beadded, either with or without additional etheralcohols, to the rubbermix during the rubber and filler processing, or mixing stages.

[0071] Another advantage of the use of etheralkoxy sulfur silanes isthat the hydrolysis of the alkoxy groups during the coupling to fillerreleases less volatile organic compounds (VOC) than is the case with theuse of conventional sulfur silanes, which in the current art typicallycontain three ethoxy groups per silicon. The etheralkoxy sulfur silaneshave at least one of the ethoxy or other alkoxy group of a volatilealcohol replaced with an etheralkoxy group. This results in the releaseof less ethanol with the use of etheralkoxy sulfur silanes than with theuse of silanes used in the current art. The release of less alcohol withthe use of etheralkoxy sulfur silanes is an advantage from anenvironmental standpoint.

[0072] The etheralkoxy sulfur silane(s) may be premixed and/orpre-reacted with the filler particles, or added to the rubber mix duringthe rubber and filler processing, or mixing stages. If the etheralkoxysulfur silanes and filler are added separately to the rubber mix duringthe rubber and filler mixing, or processing stage, it is considered thatthe etheralkoxy sulfur silane(s) then combine(s) in an in-situ fashionwith the filler.

[0073] The vulcanized rubber composition should contain a sufficientamount of filler to contribute a reasonably high modulus and highresistance to tear. The combined weight of the filler may be as low asabout 5 to 100 phr, but is more preferably from 25 to 85 phr.

[0074] Preferably, at least one precipitated silica is utilized as afiller. The silica may be characterized by having a BET surface area, asmeasured using nitrogen gas, preferably in the range of 40 to 600, andmore usually in a range of 50 to 300 m²/g. The silica typically may alsobe characterized by having a dibutylphthalate (DBP) absorption value ina range of 100 to 350, and more usually 150 to 300. Further, the silica,as well as the aforesaid alumina and aluminosilicate, may be expected tohave a CTAB surface area in a range of 100 to 220. The CTAB surface areais the external surface area as evaluated by cetyl trimethylammoniumbromide with a pH of 9. The method is described in ASTM D 3849.

[0075] Mercury porosity surface area is the specific surface areadetermined by mercury porosimetry. Using this method, mercury ispenetrated into the pores of the sample after a thermal treatment toremove volatiles. Set-up conditions may be suitably described as using a100 mg sample; removing volatiles during 2 hours at 105° C. and ambientatmospheric pressure; ambient to 2000 bars pressure measuring range.Such evaluation may be performed according to the method described inWinslow, Shapiro in ASTM bulletin, p.39 (1959) or according to DIN66133. For such an evaluation, a CARLO-ERBA Porosimeter 2000 might beused. The average mercury porosity specific surface area for the silicashould be in a range of 100 to 300 m²/g.

[0076] A suitable pore size distribution for the silica, alumina, andaluminosilicate according to such mercury porosity evaluation isconsidered herein to be such that five percent or less of its pores havea diameter of less than about 10 nm, 60 to 90 percent of its pores havea diameter of 10 to 100 nm, 10 to 30 percent of its pores have adiameter at 100 to 1,000 nm, and 5 to 20 percent of its pores have adiameter of greater than about 1,000 nm.

[0077] The silica might be expected to have an average ultimate particlesize, for example, in the range of 10 to 50 nm as determined by theelectron microscope, although the silica particles may be even smaller,or possibly larger, in size. Various commercially available silicas maybe considered for use in this invention such as, from PPG Industriesunder the HI-SIL trademark with designations HI-SIL 210, 243, etc.;silicas available from Rhone-Poulenc, with, for example, designation ofZEOSIL 1165 MP; silicas available from Degussa with, for example,designations VN2 and VN3, etc. and silicas commercially available fromHuber having, for example, a designation of HUBERSIL7 8745.

[0078] In compositions for which it is desirable to utilize siliceousfillers such as silica, alumina and/or aluminosilicates in combinationwith carbon black reinforcing pigments, the compositions may comprise afiller mix of about 15 to about 95 weight percent of the siliceousfiller, and about 5 to about 85 weight percent carbon black, wherein thecarbon black has a CTAB value in a range of 80 to 150. More typically,it is desirable to use a weight ratio of siliceous fillers to carbonblack of at least about 3/1, and preferably at least about 10/1. Theweight ratio may range from about 3/1 to about 30/1 for siliceousfillers to carbon black.

[0079] Alternatively, the filler can be comprised of 60 to 95 weightpercent of said silica, alumina and/or aluminosilicate and,correspondingly, 40 to 5 weight percent carbon black. The siliceousfiller and carbon black may be pre-blended or blended together in themanufacture of the vulcanized rubber.

[0080] In preparing the rubber compositions of the present invention,one or more of the etheralkoxy sulfur silanes are mixed with the organicpolymer before, during or after the compounding of the filler into theorganic polymer. It is preferred to add the etheralkoxy sulfur silanesbefore or during the compounding of the filler into the organic polymer,because these silanes facilitate and improve the dispersion of thefiller. The total amount of etheralkoxy sulfur silanes present in theresulting combination should be about 0.05 to about 25 parts by weightper hundred parts by weight of organic polymer (phr); more preferably 1to 10 phr. Fillers can be used in quantities ranging from about 5 toabout 100 phr, more preferably from 25 to 80 phr.

[0081] In practice, sulfur vulcanized rubber products typically areprepared by thermomechanically mixing rubber and various ingredients ina sequentially step-wise manner followed by shaping and curing thecompounded rubber to form a vulcanized product. First, for the aforesaidmixing of the rubber and various ingredients, typically exclusive ofsulfur and sulfur vulcanization accelerators (collectively, curingagents), the rubber(s) and various rubber compounding ingredientstypically are blended in at least one, and often (in the case of silicafilled low rolling resistance tires) two, preparatory thermomechanicalmixing stage(s) in suitable mixers. Such preparatory mixing is referredto as nonproductive mixing or non-productive mixing steps or stages andis usually conducted at temperatures of about 140° C. to 200° C., andfor some compositions, about 150° C. to 180° C. Subsequent to suchpreparatory mix stages, in a final mixing stage, sometimes referred toas a productive mix stage, curing agents, and possibly one or moreadditional ingredients, are mixed with the rubber compound orcomposition, at lower temperatures of typically about 50° C. to 130° C.in order to prevent or retard premature curing of the sulfur curablerubber, sometimes referred to as scorching. The rubber mixture, alsoreferred to as a rubber compound or composition, typically is allowed tocool, sometimes after or during a process intermediate mill mixing,between the aforesaid various mixing steps, for example, to atemperature of about 50° C. or lower. When it is desired to mold and tocure the rubber, the rubber is placed into the appropriate mold at atemperature of at least about 130° C. and up to about 200° C. which willcause the vulcanization of the rubber by the sulfur-containing groups ofthe etheralkoxy sulfur silanes and any other free sulfur sources in therubber mixture.

[0082] Thermomechanical mixing refers to the phenomenon whereby underthe high shear conditions in a rubber mixer, the shear forces andassociated friction occurring as a result of mixing the rubber compound,or some blend of the rubber compound itself and rubber compoundingingredients in the high shear mixer, the temperature autogeneouslyincreases, i.e. it “heats up”. Several chemical reactions may occur atvarious steps in the mixing and curing processes.

[0083] The first reaction is a relatively fast reaction and isconsidered herein to take place between the filler and the siliconalkoxide group of the etheralkoxy sulfur silanes. Such reaction mayoccur at a relatively low temperature such as, for example, at about120° C. The second reaction is considered herein to be the reactionwhich takes place between the sulfur-containing portion of thehydrocarbon core polysulfide silane, and the sulfur vulcanizable rubberat a higher temperature; for example, above about 140° C.

[0084] Another sulfur source may be used, for example, in the form ofelemental sulfur, such as, but not limited to, S_(g). A sulfur donor isconsidered herein as a sulfur containing compound that liberates free,or elemental sulfur, at a temperature in a range of 140° C. to 190° C.Such sulfur donors may be, for example, although not limited to,polysulfide vulcanization accelerators and organosilane polysulfideswith at least two connecting sulfur atoms in their polysulfide bridges.The amount of free sulfur source addition to the mixture can becontrolled or manipulated as a matter of choice relatively independentlyfrom the addition of the aforesaid etheralkoxy sulfur silanes. Thus, forexample, the independent addition of a sulfur source may be manipulatedby the amount of addition thereof and by the sequence of additionrelative to the addition of other ingredients to the rubber mixture.

[0085] A desirable rubber composition may therefore comprise about 100parts by weight of at least one sulfur vulcanizable rubber selected fromthe group consisting of conjugated diene homopolymers and copolymers,and copolymers of at least one conjugated diene and aromatic vinylcompound, about 5 to 100 parts, preferably about 25 to 80 parts perhundred parts by weight rubber of at least one particulate filler, up toabout 5 parts by weight per 100 parts by weight rubber of a curingagent, and about 0.05 to about 25 parts per hundred parts of polymer ofat least one etheralkoxy sulfur silane as described herein.

[0086] The filler preferably comprises from about 1 to about 85 weightpercent carbon black based on the total weight of the filler and 0 toabout 20 parts by weight of at least one etheralkoxy sulfur silane basedon the total weight of the filler.

[0087] The rubber composition is then prepared by first blending rubber,filler and etheralkoxy sulfur silane, or rubber, filler pretreated withall or a portion of the etheralkoxy sulfur silane and any remainingetheralkoxy sulfur silane, in a first thermomechanical mixing step to atemperature of about 140° C. to about 190-200° C. for about 2 to 20minutes, preferably about 4 to 15 minutes. Optionally, the curing agentis then added in another thermomechanical mixing step at a temperatureof about 50° C. and mixed for about 1-30 minutes. The temperature isthen heated again to between about 130° C. and about 200° C. and curingis accomplished in about 5 to about 60 minutes.

[0088] The process may also comprise the additional steps of preparingan assembly of a tire or sulfur vulcanizable rubber with a treadcomprised of the rubber composition prepared according to this inventionand vulcanizing the assembly at a temperature in a range of 130° C. to200° C.

[0089] Other optional ingredients may be added in the rubbercompositions of the present invention including curing aids, i.e.,sulfur compounds, including activators, retarders, and accelerators,processing additives such as oils, plasticizers, tackifying resins,silicas, other fillers, pigments, fatty acids, zinc oxide, waxes,antioxidants and antiozonants, peptizing agents, reinforcing materials,such as, for example, carbon black, and the like. Such additives areselected based upon the intended use and on the sulfur vulcanizablematerial selected for use, and such selection is within the knowledge ofthose skilled in the art, as are the required amounts of such additives.

[0090] The vulcanization may be conducted in the presence of additionalsulfur vulcanizing agents. Examples of suitable sulfur vulcanizingagents include, for example, elemental sulfur (free sulfur) orsulfur-donating vulcanizing agents, for example, an amino disulfide,polymeric polysulfide or sulfur olefin adducts that are conventionallyadded in the final, productive, rubber composition mixing step. Thesulfur vulcanizing agents (which are common in the art) are used, oradded in the productive mixing stage, in an amount ranging from 0.4 to 3phr, or even, in some circumstances, up to about 8 phr, with a range offrom 1.5 to 2.5 phr, sometimes from 2 to 2.5 phr, being preferred.

[0091] Optionally, vulcanization accelerators, i.e., additional sulfurdonors, may be used herein. It is appreciated that they may be, forexample, of the type such as, for example, benzothiazole, alkyl thiuramdisulfide, guanidine derivatives, and thiocarbamates. Representative ofsuch accelerators include, but are not limited to, mercaptobenzothiazole, tetramethyl thiuram disulfide, benzothiazole disulfide,diphenylguanidine, zinc dithiocarbamate, alkylphenoldisulfide, zincbutyl xanthate, N-dicyclohexyl-2-benzothiazolesulfenamide,N-cyclohexyl-2-benzothiazolesulfenamide,N-oxydiethylenebenzothiazole-2-sulfenamide, N,N-diphenylthiourea,dithiocarbamylsulfenamide, N,N-diisopropylbenzothiozole-2-sulfenamide,zinc-2-mercaptotoluimidazole, dithiobis(N-methyl piperazine),dithiobis(N-beta-hydroxy ethyl piperazine) and dithiobis(dibenzylamine). Other additional sulfur donors, may be, for example, thiuram andmorpholine derivatives. Representative of such donors include, but arenot limited to, dimorpholine disulfide, dimorpholine tetrasulfide,tetramethyl thiuram tetrasulfide, benzothiazyl-2,N-dithiomorpholide,thioplasts, dipentamethylenethiuram hexasulfide, anddisulfidecaprolactam.

[0092] Accelerators are used to control the time and/or temperaturerequired for vulcanization and to improve the properties of thevulcanizate. In one embodiment, a single accelerator system may be used,i.e., a primary accelerator. Conventionally and preferably, a primaryaccelerator(s) is used in total amounts ranging from 0.5 to 4,preferably 0.8 to 1.5, phr. Combinations of a primary and a secondaryaccelerator might be used with the secondary accelerator being used insmaller amounts (0.05 to 3 phr) in order to activate and to improve theproperties of the vulcanizate. Delayed action accelerators may be used.Vulcanization retarders might also be used. Suitable types ofaccelerators are amines, disulfides, guanidines, thioureas, thiazoles,thiurams, sulfenamides, dithiocarbamates, and xanthates. Preferably, theprimary accelerator is a sulfenamide. If a second accelerator is used,the secondary accelerator is preferably a guanidine, dithiocarbamate, orthiuram compound.

[0093] Typical amounts of tackifier resins, if used, comprise 0.5 to 10phr, usually 1 to 5 phr. Typical amounts of processing aids comprise 1to 50 phr. Such processing aids can include, for example, aromatic,napthenic, and/or paraffinic processing oils. Typical amounts ofantioxidants comprise 1 to 5 phr. Representative antioxidants may be,for example, diphenyl-p-phenylenediamine and others, such as, forexample, those disclosed in the Vanderbilt Rubber Handbook (1978), pages344-346. Typical amounts of antiozonants comprise 1 to 5 phr. Typicalamounts of fatty acids, if used, which can include stearic acid,comprise 0.5 to 3 phr. Typical amounts of zinc oxide comprise 2 to 5phr. Typical amounts of waxes comprise 1 to 5 phr. Oftenmicrocrystalline waxes are used. Typical amounts of peptizers comprise0.1 to 1 phr. Typical peptizers may be, for example,pentachlorothiophenol and dibenzamidodiphenyl disulfide.

[0094] The rubber composition of this invention can be used for variouspurposes. For example, it can be used for various tire compounds. Suchtires can be built, shaped, molded and cured by various methods that areknown and will be readily apparent to those having skill in such art.

[0095] The examples presented below demonstrate significant advantagesof the silanes described herein relative those of the currentlypracticed art, in their performance as coupling agents in silica-filledrubber. Table 1, listed in Examples 8 and 9, below, presents theperformance parameters of etheralkoxy sulfur silanes of the presentinvention and of TESPT, the silane used in the prior art which hasbecome the industry standard. It is clearly evident from the table thatSilanes 1 and 2, containing the diethylene glycol group, give rubberwith significantly improved abrasion resistance, relative to rubberprepared with the control silane, TESPT. Likewise, Silanes 1 and 2 giverubber with improved modulus, elongation, and tensile strength.

[0096] All references cited herein are incorporated by reference hereinin their entirety. The following non-limiting examples are furtherillustrative of the present invention, but are in no way intended to beconstrued as limiting the invention in any way. The advantages andimportant features of the present invention will be more apparent fromthe following examples.

EXAMPLES

[0097] Among the examples provided below are several that demonstratemethods for preparing the novel compositions of matter of the presentinvention. Many of these examples employ diethylene glycol (DEG),obtained from Uniroyal Chemical, as the ether-alcohol starting material.DEG is a diol and contains two OH groups. In the examples, DEG is usedas a source of the —OCH₂CH₂OCH₂CH₂O— group. Many of the examples alsouse A-1289, obtained from OSi Specialties, as the TESPT startingmaterial. TESPT, also known as Si-69, and often referred to asbis(3-triethoxysilyl-1-propyl)tetrasulfide orbis(3-triethoxysilyl-1-propyl)tetrasulfane, is an equilibrium ornear-equilibrium distribution of bis(3-triethoxysilyl-1-propyl)polysulfides averaging about four sulfur atoms per molecule. Often, theproduct compositions were measured by gas chromatography (GC). Some ofthe examples use a hydrous para-toluenesulfonic acid (PTSA) as an acidcatalyst.

Example 1

[0098] DEG (25 grams, 0.24 mole) and TESPT (250 grams, 0.48 mole) wereadded to a 500 mL round-bottom flask fitted with a thermometer, andstirred to obtain a homogeneous mixture. A quantity of 100 grams of thismixture was transferred to another flask whereupon 0.5 gram of a 21%ethanolic solution of sodium ethoxide was added with stirring. Thismixture was stirred under vacuum to remove ethanol. An additional 3.0grams of the ethanolic solution of sodium ethoxide was then added withstirring. The mixture was then stirred under vacuum to remove ethanol.GC analysis was consistent with conversion of more than half of theTESPT and DEG, to nominally yield a 2/1 transesterification product ofTESPT and DEG, whose average molecular composition corresponded to twoTESPT molecules, each having one of the six ethoxy groups replaced withone end of a DEG group.

Example 2

[0099] DEG (25 grams, 0.24 mole) and TESPT (250 grams, 0.48 mole) wereadded to a 500 mL round-bottom flask fitted with a thermometer, andstirred to obtain a homogeneous mixture. A quantity of 100 grams of thismixture was removed, leaving 175 grams to which was added 1.5 mL of a 2molar ethanolic solution of ammonia, with stirring. The flask wasequipped with a distillation head and heated until a pot temperature of105° C. was reached to distill off ethanol. GC analysis was consistentwith conversion of most of the TESPT and DEG. The flask and contentswere cooled and an additional 3 mL of the 2 molar ethanolic ammonia wasadded with stirring and heated to remove ethanol. This nominally yieldeda 2/1 transesterification product of TESPT and DEG, whose averagemolecular composition corresponded to two TESPT molecules, each havingone of the six ethoxy groups replaced with one end of a DEG group.

Example 3

[0100] DEG (19.5 grams, 0.18 mole) and TESPT (100 grams, 0.19 mole) wereadded to a 250 mL round-bottom flask fitted with a thermometer, andstirred to obtain a homogeneous mixture. To this was added 4.5 grams ofa 21% ethanolic solution of sodium ethoxide, with continued stirring.After four hours, the flask was equipped with a short-path condenser.The flask was then heated to a temperature of 98° C. to distill offethanol. Partial vacuum and then full vacuum was subsequently applied tostrip off remaining ethanol. Six grams of ethanol was collected. Sixgrams of Amberlite IR 120 (plus) was then added to the flask and theresulting mixture was stirred for 30 minutes. Solids in the mixture werethen removed by filtration through a 0.5 micron filter. GC analysis ofthe resulting viscous, brown liquid was consistent with conversion ofmost of the TESPT and DEG, to nominally yield a 1/1 transesterificationproduct of TESPT and DEG, whose average molecular compositioncorresponded to the TESPT molecule having two of its six ethoxy groupsreplaced with a DEG group.

Example 4

[0101] DEG (46.7 grams, 0.44 mole) and TESPT (120 grams, 0.23 mole) wereadded to a 250 mL round-bottom flask fitted with a thermometer,short-path distillation head, and stir bar, and stirred. To this wasadded 0.6 gram of PTSA. The resulting mixture was stirred and heated to80-85° C. The stirred mixture became clear at about 50° C. The flask andcontents were then cooled to 60° C. and a partial vacuum was applied toremove ethanol, which collected at a head temperature of 30° C. GCanalysis of the resulting liquid was consistent with conversion ofessentially all of the TESPT and DEG, to nominally yield a 2/1transesterification product of TESPT and DEG.

Example 5

[0102] DEG (11.7 grams, 0.11 mole) and TESPT (118.6 grams, 0.23 mole)were added to a 200 mL round-bottom flask fitted with a thermometer,short-path distillation head, and stir bar, and stirred. To this wasadded 0.1 gram of PTSA. The resulting mixture was stirred, yielding aclear, yellow liquid. This liquid was then placed under a vacuum andstirred to remove ethanol yielding a very viscous liquid with somegelling. GC analysis was consistent with conversion of most of the TESPTand DEG to nominally yield a 2/1 transesterification product of TESPTand DEG, whose average molecular composition corresponded to two TESPTmolecules, each having one of the six ethoxy groups replaced with oneend of a DEG group. The product still contained residual alcohol (4% asethanol).

Example 6

[0103] DEG (23.4 grams, 0.22 mole) and TESPT (118.6 grams, 0.23 mole)were added to a 200 mL round-bottom flask fitted with a thermometer,short-path distillation head, and stir bar, and stirred. To this wasadded 0.1 gram of PTSA. The resulting mixture was stirred, yielding acloudy, yellow liquid. This liquid was warmed initially and then stirredfor 24 hours, yielding a clear, yellow liquid. This mixture was thenplaced under a vacuum and stirred for 2 hours to remove ethanol,whereupon it became very viscous and eventually gelled a little. GCanalysis was consistent with conversion of most of the TESPT and DEG tonominally yield a 1/1 transesterification product of TESPT and DEG,whose average molecular composition corresponded to the TESPT moleculehaving two of its six ethoxy groups replaced with a DEG group.

Example 7

[0104] DEG (98 grams, 0.92 mole) and TESPT (997 grams, 1.9 moles) wereadded to a 2000 mL round-bottom flask fitted with a thermometer,short-path distillation head, and stir bar, and stirred under nitrogen.To this was added 2 grams of PTSA. The resulting hazy mixture wasstirred for 30 minutes, yielding a clear, yellow liquid. This mixturewas then placed under a vacuum and stirred for about 24 hours to removeethanol. This yielded a yellow liquid. GC analysis was consistent withconversion of more than half of the TESPT and DEG to nominally yield a2/1 transesterification product of TESPT and DEG, whose averagemolecular composition corresponded to two TESPT molecules, each havingone of the six ethoxy groups replaced with one end of a DEG group.

Examples 8 and 9

[0105] The etheralkoxy sulfur silanes prepared in Examples 1 through 7were used as the coupling agents to prepare a low rolling resistancetire tread formulation. The rubber composition used was the following,where the figures listed under the PHR heading indicate the mass of thecorresponding ingredient used relative to 100 total mass units ofpolymer (in this case, SSBR and polybutadiene) used. PHR INGREDIENT 75SSBR (12% styrene, 46% vinyl, T_(g): 42° C.) 25 cis-1,4-polybutadiene(98% cis, T_(g): 104° C.) 80 Silica (150-190 m²/gm, ZEOSIL 7 1165MP,Rhone- Poulenc) 32.5 Aromatic process oil (high viscosity, Sundex 8 125,Sun) 2.5 Zinc oxide (KADOX 7 720C, Zinc Corp) 1 Stearic acid (INDUSTRENE7, CK Witco Corp., Greenwich, CT) 2 6PPD antiozonant (SANTOFLEX7 6PPD,Flexsys) 1.5 Microcrystalline wax (M-4067, Schumann) 3 N330 carbon black(Engineered Carbons) 1.4 Sulfur (#104, Sunbelt) 1.7 CBS accelerator(SANTOCURE 7, Flexsys) 2 DPG accelerator (PERKACIT 7 DPG-C, Flexsys)

[0106] The etheralkoxy sulfur sitanes prepared by the proceduresdescribed in Examples 1-7 were used to prepare the rubber compositionsdescribed in Examples 8 and 9. Examples 8 and 9 and a control were runside by side to provide a meaningful basis of comparison for theperformance as a coupling agent in silica-filled rubber of therepresentative examples presented herein of the etheralkoxy sulfursilanes. The silane used in the control was the current industrystandard coupling agent for rubber for silica-filled tire treads, thenominal bis(3-triethoxysilyl-1-propyl)tetrasulfide (TESPT), which ismore completely described as an equilibrium or near-equilibriumdistribution of bis(3-triethoxysilyl-1-propyl) polysulfides averagingabout four sulfur atoms per molecule. The rubber compoundingformulations and procedures used in Examples 8 and 9 and in the controlwere identical with the exception of the silane used as the couplingagent. The silane loading levels used were also identical with respectto the loadings of silicon delivered by the silane. This necessitatedthe use of slightly different loading levels on an actual mass (i.e.,weight) basis owing to molecular weight differences among the silanesevaluated. The samples were prepared using a “B BANBURY” (FarrellCorporation) mixer with a 103 cu. in. (1690 cc) chamber volume. A rubbermasterbatch was prepared in a two step procedure. The mixer was set at120 rpm with the cooling water on full. The rubber polymers were addedto the mixer while running and ram down mixed for 30 seconds. For eachrubber composition prepared, approximately half of the silica (about35-40 g), and all of the silane (in an ethylvinyl acetate “EVA” bag)were added and ram down mixed for 30 seconds. The remaining silica andthe oil (in an EVA bag) were then added and ram down mixed for 30seconds. The mixer throat was dusted down three times and the mixtureram down mixed for 15 seconds each time. The mixing speed was increasedto between about 160-240 rpm as required to raise the temperature of therubber masterbatch to between about 160 and 165° C. in approximately oneminute: The masterbatch was removed from the mixer and using thiscomposition, a sheet was then formed on a roll mill set at about 50 to60° C., and then allowed to cool to ambient temperature.

[0107] The masterbatch was then again added to the mixer, with the mixerat 120 rpm and cooling water turned on full and ram down mixed for 30seconds. The remainder of the ingredients were then added and ram downmixed for 30 seconds. The mixer throat was dusted down, and the mixerspeed was increased to about 160-240 rpm in order to increase thetemperature of the mix to about 160-165° C. in approximately 2 minutes.The rubber composition was mixed for 8 minutes with adjustments to themixer speed in order to maintain the temperature between about 160-165°C. The composition was removed from the mixer and a sheet about 3 inchesthick was formed on a 6×12 inch roll mill set at about 50 to 60° C. Thissheet was then allowed to cool to ambient temperature. The resultingrubber composition was subsequently mixed with the curatives on a 6in.×13 in. (15 cm×33 cm) two roll mill that was heated to between 50 and60° C. The sulfur and accelerators were then added to the compositionand thoroughly mixed on the roll mill and allowed to form a sheet. Thesheet was cooled to ambient conditions for 24 hours before it was cured.

[0108] The rheological properties of the rubber compound so preparedwere measured on a Monsanto R-100 Oscillating Disk Rheometer and aMonsanto M1400 Mooney Viscometer. The specimens for measuring themechanical properties were cut from 6 mm plaques cured for 35 minutes at160° C. or from 2 mm plaques cured for 25 minutes at 160° C. The silaneswere compounded into the tire tread formulation according to the aboveprocedure. In both Examples 8 and 9, the etheralkoxy sulfur silaneprepared in Example 5 was used. Example 8 differed from Example 9 onlyin that Example 9 included the addition of 1.3 phr diethylene glycolwith the etheralkoxy sulfur silane, whereas Example 8 did not.

[0109] The samples of the present invention were tested against acontrol sample that is nominallybis-(3-triethoxysilyl-1-propyl)tetrasulfide (TESPT), an industrystandard coupling agent. Its actual composition is a mixture ofpolysulfides, with significant contributions from individual speciescontaining chains of from 2 to 8 sulfur atoms. The compositions weretested using standard testing procedures. The results of the testing aresummarized in Table 1 below.

Test Methods

[0110] 1. Mooney Scorch

[0111] ASTM D1646

[0112] 2. Mooney Viscosity

[0113] ASTM DI 646

[0114] 3. Oscillating Disc Rheometer (ODR)

[0115] ASTM D2084

[0116] 4. Physical Properties; Storage Modulus, Loss Modulus, Tensile &Elongation

[0117] ASTM D412 and D224.

[0118] 5. DIN Abrasion

[0119] DIN Procedure 53516.

[0120] 6. Heat Build-Up

[0121] ASTM D623

[0122] Heat build-up was measured at 100° C. using an 18.5% compression,143 psi load and a 25 minute run. A sample, which was at ambientconditions, was placed in an oven that had been preheated to 100° C. Thesample was conditioned at 100° C. for 20 minutes and then given a 5minute test run.

[0123] 7. % Permanent Set

[0124] ASTM D623

[0125] 8. Shore A Hardness

[0126] ASTM D2240 TABLE 1 Properties and Processing Parameters ofCompounded Rubbers Example 8 Example 9 Control Sample Silane 1 Silane 2TESPT Silane: Type and Amount 2/1 TESPT/ 2/1 TESPT/ TESPT DEG DEG Ex. 5Silane Ex. 5 Silane Silane Loading (PHR) 7.4 7.4 7.0 Additional DEGLoading (PHR) 0 1.3 0 Silane Si Loading, 0.027 0.027 0.027 moles Si/100g. rubber Mooney Viscosity @ 67 63 67 100° C. (ML1 + 4) Mooney Scorch @135° C., minutes M_(v) 35.9 33.5 36.9 MS1 + t₃ 15.0 18.5 6.2 MS1 + t₁₈18.4 22.2 9.5 ODR @ 149° C., 1° Arc; 30 minutes M_(L), lb-in 9.4 8.7 8.7M_(H), lb-in 32.6 34.2 31.0 t_(s1), minutes 7.1 6.2 4.0 t₉₀, minutes21.0 21.1 16.4 Physical Properties; 90 minute cure @ 149° C. Shore AHardness 60 61 59 % Elongation 476 473 434  25% Modulus, psi 133 138 125100% Modulus, psi 336 354 302 300% Modulus, psi 1916 1933 1859 TensileStrength, psi 3516 3553 3316 Modulus Ratio (300%/25%) 14.4 14.0 14.9Modulus Ratio (300%/100%) 5.70 5.50 6.20 DIN Abrasion, mm 109 105 126Heat Build-up @ 100° C., 17.5% compression, 143 psi static load, 25minute run Delta T, ° C. 14 13 18 % Permanent Set 5.3 5.4 8.2 Low-StrainDynamic Properties: Simple Shear @ 60° C. and 5.0 N Compressive NormalForce G′_(0%strain), MPa** 3.54 3.49 3.12 ΔG′ = G′_(0%strain) −G′_(10%strain), MPa 1.78 1.74 1.52 G″_(max), MPa 0.417 0.396 0.328Maximum tan δ value 0.182 0.171 0.168 High-Strain Dynamic Properties @35% Dynamic Strain Amplitude (DSA) tan δ @ 60° C. (Hysteresis) 0.1250.115 0.125

[0127] In view of the many changes and modifications that can be madewithout departing from principles underlying the invention, referenceshould be made to the appended claims for an understanding of the scopeof the protection to be afforded the invention.

What is claimed is:
 1. A composition of matter comprising at least onesilane coupling agent for coupling an elastomer and a filler whereinsaid silane comprises at least one hydrolysable group that, uponcompounding said silane with said elastomer and filler, is released toyield a compound that improves downstream processability of thecompounded composition or the properties of the final rubber product orboth.
 2. The composition of claim 1 wherein said silane coupling agentis selected from the group consisting of silanes whose individualstructures are represented by at least one of the following generalformulae: [J-S-G¹-(SiX²X³)][—Y²—(X²Si-G¹-S-J)]_(m)-X^(1.);  Formula 1:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²Si)-G²S_(x)-G³-(SiX¹X²X³)]_(m)—X^(1.);  Formula2:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²X³Si)-G²-S_(x)-G³-(SiX²X³)]_(n)—X^(1.);and  Formula 3: [(—Y²—)_(y/2)(X² _(3-h)Si)-G¹-S-J]_(m)[(—Y²—)_(j/2)(X²_(3-j)Si)-G²-S_(x)-G³-(SiX² _(3-k))(—Y²—)_(k/2)]_(n)  Formula 4:wherein, in formulae 1 through 4: each occurrence of the subscript, h,is independently an integer from 1 to 3; each separate occurrence of thesubscripts, j and k, is independently an integer from 0 to 3, with theproviso that j+k>0; each occurrence of the subscript, m, isindependently an integer from 1 to 1000; each occurrence of thesubscript, n, is independently an integer from 1 to 1000; eachoccurrence of the subscript, x, is independently an integer from 2 to20; each occurrence of X¹ is independently selected from the group ofhydrolysable moieties consisting of —Y¹, —OH, —OR¹, and R¹C(═O)O—,wherein each occurrence of R¹ is independently any hydrocarbon fragmentobtained by removal of one hydrogen atom from a hydrocarbon having from1 to 20 carbon atoms, and R¹ includes aryl groups and any branched orstraight chain alkyl, alkenyl, arenyl, or aralkyl groups; eachoccurrence of X² and X³ is independently selected from the groupconsisting of hydrogen, R¹, and X¹; each occurrence of G¹, G², and G³ isindependently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); each occurrence of J is independently selectedfrom the group consisting of R¹C(═O)—, R¹C(═S)—, R¹ ₂P(═O)—, R¹ ₂P(═S)—,R¹S(═O)—, and R¹S(═O)₂—, wherein each separate occurrence of R¹ is asdefined above; each occurrence of Y¹ is independently —O-G-(O-G-)_(p)ORor —O-G-(O-G-)_(p)OH and each occurrence of Y² is independently—O-G-(O-G-)_(q)O—, each occurrence of the subscript, p, is independentlyan integer from 1 to 100; each occurrence of the subscript, q, isindependently an integer from 1 to 100; each occurrence of G isindependently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); and each occurrence of R is independentlyselected from the group consisting of the members listed above for R¹.3. The composition of claim 2 wherein G¹, G², and G³ are independentlyselected from the group consisting of terminal straight-chain alkylsfurther substituted terminally at the opposite end and theirbeta-substituted analogs; a structure derivable from methallyl chloride;any of the structures derivable from divinylbenzene; any of thestructures derivable from dipropenylbenzene; any of the structuresderivable from butadiene; any of the structures derivable frompiperylene; any of the structures derivable from isoprene; any of theisomers of —CH₂CH₂-norbornyl- or —CH₂CH₂-cyclohexyl-; any of thediradicals obtainable from norbornane, cyclohexane, cyclopentane,tetrahydrodicyclopentadiene, or cyclododecene by loss of two hydrogenatoms; any of the structures derivable from limonene; any of themonovinyl-containing structures derivable from trivinylcyclohexane; anyof the monounsaturated structures derivable from myrcene containing atrisubstituted C═C; and any of the monounsaturated structures derivablefrom myrcene lacking a trisubstituted C═C.
 4. The composition of claim 3wherein G¹, G², and G³ are independently selected from the groupconsisting of —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH(CH₃)CH₂—, and any ofthe diradicals obtained by 2,4 or 2,5 disubstitution ofnorbornane-derived structures.
 5. The composition of claim 2 wherein X¹is selected from the group consisting of methoxy, ethoxy, propoxy,isopropoxy, butoxy, phenoxy, benzyloxy, hydroxy, chloro, and acetoxy. 6.The composition of claim 2 wherein X² and X³ are independently selectedfrom the group consisting of methoxy, ethoxy, isopropoxy, methyl, ethyl,phenyl, and the higher straight-chain alkyls.
 7. The composition ofclaim 2 wherein X¹, X², and X³ are all the same alkoxy group.
 8. Thecomposition of claim 2 wherein G is selected from the group consistingof terminal straight-chain alkyls further substituted terminally at theopposite end, their beta-substituted analogs, and analogs with more thanone methyl substitution; any of the structures derivable fromdivinylbenzene; any of the structures derivable from dipropenylbenzene;any of the structures derivable from butadiene; any of the structuresderivable from piperylene; any of the structures derivable fromisoprene; any of the monovinyl-containing structures derivable fromtrivinylcyclohexane; any of the monounsaturated structures derivablefrom myrcene containing a trisubstituted C═C; and any of themonounsaturated structures derivable from myrcene lacking atrisubstituted C═C.
 9. A composition comprising: A) at least oneelastomer; B) at least one filler; and C) at least one silane couplingagent for coupling the elastomer and the filler wherein the silanecomprises at least one hydrolysable group that, upon compounding saidsilane with said elastomer and filler, is released to yield a compoundthat improves downstream processability of the compounded composition orthe properties of the final rubber product or both.
 10. The compositionof claim 9 wherein said silane coupling agent is selected from the 2group consisting of silanes whose individual structures are representedby at least one of the 3 following general formulae:[J-S-G¹-(SiX²X³)][—Y²—(X²Si-G¹-S-J)]_(m)-X^(1.);  Formula 1:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²Si)-G²S_(x)-G³-(SiX¹X²X³)]_(m)—X^(1.);  Formula2:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²X³Si)-G²-S_(x)-G³-(SiX²X³)]_(n)—X^(1.);and  Formula 3: [(—Y²—)_(y/2)(X² _(3-h)Si)-G¹-S-J]_(m)[(—Y²—)_(j/2)(X²_(3-j)Si)-G²-S_(x)-G³-(SiX² _(3-k))(—Y²—)_(k/2)]_(n)  Formula 4:wherein, in formulae 1 through 4: each occurrence of the subscript, h,is independently an integer from 1 to 3; each separate occurrence of thesubscripts, j and k, is independently an integer from 0 to 3, with theproviso that j+k>0; each occurrence of the subscript, m, isindependently an integer from 1 to 1000; each occurrence of thesubscript, n, is independently an integer from 1 to 1000; eachoccurrence of the subscript, x, is independently an integer from 2 to20; each occurrence of X¹ is independently selected from the group ofhydrolysable moieties consisting of —Y¹, —OH, —OR¹, and R¹C(═O)O—,wherein each occurrence of R¹ is independently any hydrocarbon fragmentobtained by removal of one hydrogen atom from a hydrocarbon having from1 to 20 carbon atoms, and R¹ includes aryl groups and any branched orstraight chain alkyl, alkenyl, arenyl, or aralkyl groups; eachoccurrence of X² and X³ is independently selected from the groupconsisting of hydrogen, R¹, and X^(1.); each occurrence of G¹, G², andG³ is independently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); each occurrence of J is independently selectedfrom the group consisting of R¹C(═O)—, R¹C(═S)—, R¹ ₂P(═O)—, R¹ ₂P(═S)—,R¹S(═O)—, and R¹S(═O)₂—, wherein each separate occurrence of R¹ is asdefined above; each occurrence of Y¹ is independently —O-G-(O-G-)_(p)ORor —O-G-(O-G-)_(p)OH and each occurrence of Y² is independently—O-G-(O-G-)_(q)O—, each occurrence of the subscript, p, is independentlyan integer from 1 to 100; each occurrence of the subscript, q, isindependently an integer from 1 to 100; each occurrence of G isindependently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); and each occurrence of R is independentlyselected from the group consisting of the members listed above for R¹.11. The composition of claim 10 wherein G¹, G², and G³ are independentlyselected from the group consisting of terminal straight-chain alkylsfurther substituted terminally at the opposite end and theirbeta-substituted analogs; a structure derivable from methallyl chloride;any of the structures derivable from divinylbenzene; any of thestructures derivable from dipropenylbenzene; any of the structuresderivable from butadiene; any of the structures derivable frompiperylene; any of the structures derivable from isoprene; any of theisomers of —CH₂CH₂-norbornyl- or —CH₂CH₂-cyclohexyl-; any of thediradicals obtainable from norbornane, cyclohexane, cyclopentane,tetrahydrodicyclopentadiene, or cyclododecene by loss of two hydrogenatoms; any of the structures derivable from limonene; any of themonovinyl-containing structures derivable from trivinylcyclohexane; anyof the monounsaturated structures derivable from myrcene containing atrisubstituted C═C; and any of the monounsaturated structures derivablefrom myrcene lacking a trisubstituted C═C.
 12. The composition of claim11 wherein G¹, G², and G³ are independently selected from the groupconsisting of —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH(CH₃)CH₂—, and any ofthe diradicals obtained by 2,4 or 2,5 disubstitution ofnorbornane-derived structures.
 13. The composition of claim 10 whereinX¹ is selected from the group consisting of methoxy, ethoxy, propoxy,isopropoxy, butoxy, phenoxy, benzyloxy, hydroxy, chloro, and acetoxy.14. The composition of claim 10 wherein X² and X³ are independentlyselected from the group consisting of methoxy, ethoxy, isopropoxy,methyl, ethyl, phenyl, and the higher straight-chain alkyls.
 15. Thecomposition of claim 10 wherein X¹, X², and X³ are all the same alkoxygroup.
 16. The composition of claim 10 wherein G is selected from thegroup consisting of terminal straight-chain alkyls further substitutedterminally at the opposite end, their beta-substituted analogs, andanalogs with more than one methyl substitution; any of the structuresderivable from divinylbenzene; any of the structures derivable fromdipropenylbenzene; any of the structures derivable from butadiene; anyof the structures derivable from piperylene; any of the structuresderivable from isoprene; any of the monovinyl-containing structuresderivable from trivinylcyclohexane; any of the monounsaturatedstructures derivable from myrcene containing a trisubstituted C═C; andany of the monounsaturated structures derivable from myrcene lacking atrisubstituted C═C.
 17. A method for coupling an elastomer and a fillercomprising employing at least one silane coupling agent wherein saidsilane comprises at least one hydrolysable group that, upon compoundingsaid silane with said elastomer and filler, is released to yield acompound that improves downstream processability of the compoundedcomposition or the properties of the final rubber product or both. 18.The method of claim 17 wherein said silane coupling agent is selectedfrom the group consisting of silanes whose individual structures arerepresented by at least one of the following general formulae:[J-S-G¹-(SiX²X³)][—Y²—(X²Si-G¹-S-J)]_(m)-X^(1.);  Formula 1:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²Si)-G²S_(x)-G³-(SiX¹X²X³)]_(m)—X^(1.);  Formula2:[X¹X²X³Si-G²-S_(x)-G³-Si(X²X³)][—Y²—(X²X³Si)-G²-S_(x)-G³-(SiX²X³)]_(n)—X^(1.);and  Formula 3: [(—Y²—)_(y/2)(X² _(3-h)Si)-G¹-S-J]_(m)[(—Y²—)_(j/2)(X²_(3-j)Si)-G²-S_(x)-G³-(SiX² _(3-k))(—Y²—)_(k/2)]_(n)  Formula 4:wherein, in formulae 1 through 4: each occurrence of the subscript, h,is independently an integer from 1 to 3; each separate occurrence of thesubscripts, j and k, is independently an integer from 0 to 3, with theproviso that j+k>0; each occurrence of the subscript, m, isindependently an integer from 1 to 1000; each occurrence of thesubscript, n, is independently an integer from 1 to 1000; eachoccurrence of the subscript, x, is independently an integer from 2 to20; each occurrence of X¹ is independently selected from the group ofhydrolysable moieties consisting of —Y¹, —OH, —OR¹, and R¹C(═O)O—,wherein each occurrence of R¹ is independently any hydrocarbon fragmentobtained by removal of one hydrogen atom from a hydrocarbon having from1 to 20 carbon atoms, and R¹ includes aryl groups and any branched orstraight chain alkyl, alkenyl, arenyl, or aralkyl groups; eachoccurrence of X² and X³ is independently selected from the groupconsisting of hydrogen, R¹, and X^(1.); each occurrence of G¹, G², andG³ is independently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); each occurrence of J is independently selectedfrom the group consisting of R¹C(═O)—, R¹C(═S)—, R¹ ₂P(═O)—, R¹ ₂P(═S)—,R¹S(═O)—, and R¹S(═O)₂—, wherein each separate occurrence of R¹ is asdefined above; each occurrence of Y¹ is independently —O-G-(O-G-)_(p)ORor —O-G-(O-G-)_(p)OH and each occurrence of Y² is independently—O-G-(O-G-)_(q)O—, each occurrence of the subscript, p, is independentlyan integer from 1 to 100; each occurrence of the subscript, q, isindependently an integer from 1 to 100; each occurrence of G isindependently selected from the group consisting of hydrocarbonfragments obtained by removal of one hydrogen atom of any of the groupslisted above for R^(1.); and each occurrence of R is independentlyselected from the group consisting of the members listed above for R¹.19. A method for preparing a silane coupling agent for coupling anelastomer and a filler wherein said silane comprises at least onehydrolysable group that, upon compounding said silane with saidelastomer and filler, is released to yield a compound that improvesdownstream processability of the compounded composition or theproperties of the final rubber product or both, wherein said methodcomprises transesterifying TESPT with a polyalkylene glycol.
 20. Themethod of claim 19 wherein the polyalkylene glycol is diethylene glycol.21. The method of claim 19 further comprising carrying out thetransesterification reaction in the presence of a catalyst.
 22. Themethod of claim 21 wherein the catalyst is para-toluenesulfonic acid.